[PATCH RESEND V3 net-next 3/3] selftests/net: reap zerocopy completions passed up as ancillary data.

[Sowmini Varadhan]

PF_RDS sockets pass up cookies for zerocopy completion as ancillary
data. Update msg_zerocopy to reap this information.

Signed-off-by: Sowmini Varadhan <sowmini.varad...@oracle.com>
Acked-by: Willem de Bruijn <will...@google.com>
Acked-by: Santosh Shilimkar <santosh.shilim...@oracle.com>
---
v2: receive zerocopy completion notification as POLLIN
v3: drop ncookies arg in do_process_zerocopy_cookies; Reverse christmas
    tree declarations; check for C_TRUNC; print warning when encountering
    ignored cmsghdrs in do_recvmsg_completion

 tools/testing/selftests/net/msg_zerocopy.c |   65 ++++++++++++++++++++++++---
 1 files changed, 57 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/net/msg_zerocopy.c 
b/tools/testing/selftests/net/msg_zerocopy.c
index eff9cf2..406cc70 100644
--- a/tools/testing/selftests/net/msg_zerocopy.c
+++ b/tools/testing/selftests/net/msg_zerocopy.c
@@ -344,7 +344,53 @@ static int do_setup_tx(int domain, int type, int protocol)
        return fd;
 }
 
-static bool do_recv_completion(int fd)
+static uint32_t do_process_zerocopy_cookies(struct rds_zcopy_cookies *ck)
+{
+       int i;
+
+       if (ck->num > RDS_MAX_ZCOOKIES)
+               error(1, 0, "Returned %d cookies, max expected %d\n",
+                     ck->num, RDS_MAX_ZCOOKIES);
+       for (i = 0; i < ck->num; i++)
+               if (cfg_verbose >= 2)
+                       fprintf(stderr, "%d\n", ck->cookies[i]);
+       return ck->num;
+}
+
+static bool do_recvmsg_completion(int fd)
+{
+       char cmsgbuf[CMSG_SPACE(sizeof(struct rds_zcopy_cookies))];
+       struct rds_zcopy_cookies *ck;
+       struct cmsghdr *cmsg;
+       struct msghdr msg;
+       bool ret = false;
+
+       memset(&msg, 0, sizeof(msg));
+       msg.msg_control = cmsgbuf;
+       msg.msg_controllen = sizeof(cmsgbuf);
+
+       if (recvmsg(fd, &msg, MSG_DONTWAIT))
+               return ret;
+
+       if (msg.msg_flags & MSG_CTRUNC)
+               error(1, errno, "recvmsg notification: truncated");
+
+       for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+               if (cmsg->cmsg_level == SOL_RDS &&
+                   cmsg->cmsg_type == RDS_CMSG_ZCOPY_COMPLETION) {
+
+                       ck = (struct rds_zcopy_cookies *)CMSG_DATA(cmsg);
+                       completions += do_process_zerocopy_cookies(ck);
+                       ret = true;
+                       break;
+               }
+               error(0, 0, "ignoring cmsg at level %d type %d\n",
+                           cmsg->cmsg_level, cmsg->cmsg_type);
+       }
+       return ret;
+}
+
+static bool do_recv_completion(int fd, int domain)
 {
        struct sock_extended_err *serr;
        struct msghdr msg = {};
@@ -353,6 +399,9 @@ static bool do_recv_completion(int fd)
        int ret, zerocopy;
        char control[100];
 
+       if (domain == PF_RDS)
+               return do_recvmsg_completion(fd);
+
        msg.msg_control = control;
        msg.msg_controllen = sizeof(control);
 
@@ -409,20 +458,20 @@ static bool do_recv_completion(int fd)
 }
 
 /* Read all outstanding messages on the errqueue */
-static void do_recv_completions(int fd)
+static void do_recv_completions(int fd, int domain)
 {
-       while (do_recv_completion(fd)) {}
+       while (do_recv_completion(fd, domain)) {}
 }
 
 /* Wait for all remaining completions on the errqueue */
-static void do_recv_remaining_completions(int fd)
+static void do_recv_remaining_completions(int fd, int domain)
 {
        int64_t tstop = gettimeofday_ms() + cfg_waittime_ms;
 
        while (completions < expected_completions &&
               gettimeofday_ms() < tstop) {
-               if (do_poll(fd, POLLERR))
-                       do_recv_completions(fd);
+               if (do_poll(fd, domain == PF_RDS ? POLLIN : POLLERR))
+                       do_recv_completions(fd, domain);
        }
 
        if (completions < expected_completions)
@@ -503,13 +552,13 @@ static void do_tx(int domain, int type, int protocol)
 
                while (!do_poll(fd, POLLOUT)) {
                        if (cfg_zerocopy)
-                               do_recv_completions(fd);
+                               do_recv_completions(fd, domain);
                }
 
        } while (gettimeofday_ms() < tstop);
 
        if (cfg_zerocopy)
-               do_recv_remaining_completions(fd);
+               do_recv_remaining_completions(fd, domain);
 
        if (close(fd))
                error(1, errno, "close");
-- 
1.7.1